wich is the better posi unit. which one would last longer.

 

The Eaton is better. I have an Auburn and my brother has an Eaton. The auburn uses cone clutches that last a long time but can't be rebuilt. The eaton uses carbon fiber clutches that last a long time and can be replaced, in addition it needs no friction modifier, doesn't chatter, and has available different preload springs to make it tighter or looser.
The auburn is about $320 and the eaton was somewhere close to or in the $500 range.

 

is the auburn a good unit to but. will it last a long time. see i don't have $500 to spend. i almost have enough to get auburn. will that one last. thanks

 

I just bought a Powertrax Posi. $309 at Summit. Should be here today. Easy to put in. The other 2 units have to be put in by a pro. Unless you know how to set up a rearend. Just a thought.
Quick and easy.

Brad...

 

i thought the Aurburn was a direct bolt up to the stock rear. what is the part number for the powertax posi. i'll look into that one to. is it any good. does it just bolt up to the original rear once you take out the old carrior. i'm looking to unbolt the old carrior and get rid of that one and put a new one in. i dont want to rebuild the original. thanks alot for the help.

 

I actually wrote a report on the different differentials for a class. It doesn't like the attatchment, so if you want it, e-mail me.

 

I'm running the Auburn Pro-Series and am very happy with it. As stated it's a cone type whch I can best describe in difference as this:

If you like to break sideways(and who deosn't) then the Eaton will give you a smoother straightening out b/c of the spring/clutch setup. It can ease up on the "grip" where as the Auburn is more like it's either providing differential or it's locked together. It's not rough like a locker but that's the best way I can describe it. Either way I say you'll be happy but breaking sideways is harder on the Auburn unit as I was told. It has to due with what I said above about the variable spring/clutch pressures. I was also told the Auburn will "hold"(lock) harder since there are no springs/clutches but the cone fit instead. That is why I chose that unit, I don't care about road racing though it is 100% smooth during normal driving. For auto-X get the Eaton without question. For drag racing I'd go with the Auburn Pro-Series.

Rebuilding the units isn't an issue unless you're the burnout king doing it everyday. My old factory Eaton went 107,000 and was still working great when I removed it. Lasting that long I have no problem in buying a new one at those intervals.

 

If you don't have the money get the auburn high performance series, this is what I have in an 8.5 rear in my nova. The pro series is around $400. (I think it's rebuildable though)
I had an original cone posi for a long time and never had a problem with it. Used to beat the hell out of it with a 406 and a four speed.
Be sure to use GM friction modifier with it or the auburn will chatter bad.
They used the auburn in many GM factory posi units of the early 70's but if there was a problem with it there was a service bulliten saying they had to change it to an eaton unit instead of repairing it.

 

Get the Powertrax. Only $309 and you can put it in yourself in about 2 hours. My rear is a 3:42 7 5/8" rear. Part number for that is PWT-1932.

Brad...

 

all i am looking for is something that will drive good, and when i have to beat on it, it will take the beating. as far as the carrior, all i ment was that i don't want to rebiuld the old one. due the posi's come already in a new carrior. so i can just bolt it up.

 

The powertrax is a direct/easy bolt on. The rest are not.

Brad...

 

i heard that powertrax is for open rears only. is this true.

 

Yup. That is correct. I just got mine tonight. Might put it in this weekend. Looks pretty easy. Do you have an open rear?

Brad...

 

If you have a posi differential you want to replace it's not that difficult. Installing a new posi requires checking backlash only, this can be done with a dial indicator, if you're real desparate you can do it by tooth contact pattern with oil paint.
You'll need new bearings pressed on the sides of the posi, you can do it with a piece of pipe or big socket, or take just these parts to someone.
The ring gear needs to be put on the new unit.
Pull the rear cover, remove the wheels and brake drums, remove the cross pin bolt then the cross pin, push the axles in and rotate until you hear the c-clip fall then pull the axle out. Now mark the bearing caps and shims because they need to go back in the same locations. remove the caps and the differential will come out.
Remove the ring gear bolts and ring gear, clean everything and put it back together.
Sounds easy, the worst that can happen is you'll need different side bearing shims. Order them from Reider Racing, they have the better ones. :lala:

 

We sell Auburn, Eaton, and Powertrax. Most opt for Auburn, but Eaton follows a close second. They are all quality, and sometimes one is better than another for a specific application. I suggest emailing what you have now and what you want for an end result. It helps in determining the best choice for your application.

 

I bought my car with an Auburn rear. Less than a yr after buying the car I had my passenger side of axle slide out and almost drop my car. After having it towed I was told it would only cost 700$ cause it had to be professionally installed. Now I still have problems with it. I would definitely suggest Eaton.

 

That would be an install problem, not a product problem. I do not know who installed it, but I suspect something was amiss. I stand by Auburn and Eaton. Sometimes the application can play a role, but overall both are good products.

 

I used to run 12.8 in the 1/4 with a '75 nova with a 1968 8.2 rear with it's original auburn posi. It had a fourspeed manual. I broke several u-joints, a set of ring gear bolts,spider gears and eventually the t-10 fourspeed. The axles never came out though.
My brother has an Eaton, carbon fiber clutches ,no chatter. No need for friction modifier. My old auburn still worked when I got rid of the whole rear, the rear end case was distorted.

 

i have an original posi. so the powertrax is out of the question.

 

I have the auburn pro series, and let me say it kicks a.. I had it in my 450 hp s-10. No problems. It hooks hard and straight. I took it out when I sold chassis as it is goin in my 91rs project chassis.

 

We have not had any complaints here either.
Cruise our site www.rearman.com . Feel free to email houser@rearman.com . I base my comments from over 4000 complete rears per year since 1973, plus customer purchases of parts, third members, and rear service. We see LOTS of Camaros and Firebirds every week. (One of the many things I love about this job!)

By the way, Auburn 3- and 4-series are running $350, and Eaton $325 at present...

 

I've had, and still do have eaton posi. All of mine required the friction lube to keep from chattering. My 77 T/a sat for 12 years and it had to be torn down to clean all of the discs, before it would stop chattering.

 

Your Eaton posi was 21 years old when my brother got his Eaton, it clearly says in the instructions friction modifier is not needed, the tech at Randy's ring and pinion told him it has carbon fiber clutches. Eaton and most companies are constantly improving their products, I would assume they would have made a few changes in the past 25 years.